class Prower{
    change(){
        return "220w"
    }
}

class Adptor{
    constructor(power){
        this.power = new Prower();
    }
    change(){
        let v = this.power.change();
        return `${v}=>12v`
    }
}

class Cilent{
    constructor(){
        this.adapter = new Adptor()
    }
    use(){
        console.log(this.adapter.change());

    }
}

let oo = new Cilent();
console.log(oo.use())